Top 3 Reasons Why Your Dishwasher Won’t Drain

By Terry Mehilos | Feb. 02, 2024 1:03 am PST

Photo of an open Kenmore dishwasher in white modern kitchen

Updated February 2, 2024.

How do you unclog a dishwasher? Read about the most common reasons a dishwasher won’t drain and get expert tips for fixing the problem.

If you’ve ever opened your dishwasher door, only to find standing dirty water at the bottom of the tub, you’ve got a drainage problem. According to Sears Home Services expert Ron Meixner, there are several reasons for a clogged dishwasher.

  1. Clogged air gap on your kitchen sink.
  2. Clogged dishwasher drain hose.
  3. Kinked drain hose between the dishwasher and sink drain.

Here are helpful solutions to fix these 3 common problems that clog your dishwasher’s drain system.

1. The air gap is clogged

Some dishwashers use air gaps to prevent dirty water from backing up and contaminating your dishes. If one gets clogged, it can impact the appliance’s ability to drain. To tell if your dishwasher has an air gap, look for a small silver cylinder sitting by your faucet. If you have one, check to see if it’s clogged by removing the top cover and pulling straight up. Then, depending on the design, unscrew or release the tabs on the inner cap. Remove any debris or food buildup that may have accumulated and then reassemble the air gap.

2. The drain dishwasher hose is clogged

The dishwasher drain hose is most likely to clog where it connects to the drain underneath the sink. Loosen the drain hose clamp and carefully disconnect it from the drain tee, air gap or garbage disposal drain port. Inspect and clean any debris or food buildup from the drain connector or the end of the drain hose. Then reconnect it and tighten the hose clamp.

3. The drain hose is kinked

First check to see if the issue is where the hose connects to the drain underneath the sink, as kinks commonly happen here if the weight of the hose isn’t supported properly. Kinks also occur where the hose passes through the cabinet underneath the sink to connect the dishwasher to the drain, as well as if there’s excess drain hose coiled behind or underneath the dishwasher. Inspect the dishwasher drain hose in these three areas to make sure there are no sharp bends in the hose. Remove the kinks and test dishwasher drain operation.

Additional Troubleshooting Tips to Unclog the Dishwasher

When the above tips don’t help you unclog your dishwasher, follow the comprehensive troubleshooting tips shown in this DIY video for fixing a dishwasher that won’t drain:

If you’re unable to find and clear the dishwasher clog yourself, schedule service and we’ll send a Sears Home Services Technician to fix your dishwasher.

How to prevent dishwasher clogs in the future

To prevent future dishwasher blockages, always scrape away your dishes before placing them in the dishwasher. You don’t want to thoroughly clean the dishes before washing, but getting the larger chunks of food off will ensure your drain hose stays clear.

Make sure the water to your dishwasher is hot by running the hot water at the kitchen sink first. Always use detergent made for dishwashers, and keep you dishwasher filter clean by following the instructions in your owner’s manual.

Frequently Asked Questions About Dishwasher Draining Issues

Why is there standing water in the bottom of my dishwasher?

There are many reasons your dishwasher won’t drain. If you’ve checked for an air gap or drain hose clog and for a kinked drain hose, it’s possible your dishwasher’s filter may be blocked. The filter prevents large food particles from entering the drain pump. The dishwasher filter should be cleaned periodically to prevent food debris from building up.

Sometimes a clogged dishwasher isn’t a dishwasher issue. Unground food in garbage disposal could be blocking the dishwasher drain water. Try turning on the garbage disposal to grind away anything stuck there. It’s always a good idea when using the garage disposal to leave it on for a seconds after grinding is complete and allow the water to continue running through the sink drain to remove any leftover food sludge. If you’ve recently installed the garbage disposal, make sure the dishwasher drain knockout plug was removed.

If you’ve checked everything else, it’s possible the drain valve isn’t working correctly. Have a service technician inspect the dishwasher to determine the issue.

Can I force my dishwasher to drain?

Unfortunately, there is no way to force the dishwasher to drain to remove the standing water. If you’re not able to get the water at the bottom of the dishwasher to drain with the tips above, you’ll need to manually remove the water by bailing it. Remember to put towels down to protect your flooring before you start.

Dishwasher not draining? Sears Home Services Has Dishwasher Repair Experts

If you’re not able to find the blockage and can’t get the dishwasher to drain after troubleshooting, schedule an appointment with a repair expert. The technician will thoroughly inspect your dishwasher to identify the issue and fix it for you promptly. Sears Home Services has been in the appliance repair business for decades, and our tradition of highly-trained and highly-skilled service technicians continues today.

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